<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8">
    <title>Example</title>
</head>

<body>
    <script type="text/javascript">
    var firstVal = null;
    var secondVal;

    var equality = firstVal == secondVal;
    var identity = firstVal === secondVal;

    document.writeln("Equality: " + equality);
    document.writeln("Identity: " + identity);
    </script>
</body>

</html>
